Apparatus for deburring foundry cores and similar workpieces

ABSTRACT

An apparatus for deburring foundry cores (3) and similar workpieces, comprising a vibration device, a stationary base (10) which carries the vibration device, and a deburring template (4), is designed and constructed for an effective deburring with a reduced risk of damage to the workpiece, and with less wear on tools such that the vibrating movement of the vibration device occurs exclusively in vertical direction, and that a clearance is absent between the contours of the cores (3) to be deburred and the contours of the deburring template (4), so that the burr is cut off as the core (3) passes through the deburring template (4).

The invention relates to an apparatus for deburring foundry cores andsimilar workpieces, comprising a vibration device, a stationary basecarrying the vibration device, and a deburring template.

U.S. Pat. No. 4.590,636 discloses an apparatus of the above-describedkind, in which the burr of the foundry core is hammered off by avibrating movement. To realize the hammering movement of a debuttingtemplate, an adequate clearance is present between the latter and thecore to be deburred. Depending on the formation of the burrs on thecore, the vibrating movement to be realized there is a compositemovement, so that the burrs are hammered off all around by the deburringtemplate. Apart from the fact that automation of operations is renderedimpossible, the known apparatus is further problematic, inasmuch as theburr on the sand core which possesses mostly little strength, isvibrated or hammered off by a shock effect. Such a removal of burrsendangers the core considerably and leads, as a result of periodicallyoccurring pulses, to the necessity of a costly mechanism for avoidingtransmissions of vibration.

Based on the problems arising in the state of the art with respect tothe deburring operations subjecting both the tool and the workpiece toconsiderable stress, the teaching of the invention is based on theobject of configuring and further developing the known apparatus fordeburring foundry cores and similar workpieces such that an effectiveremoval of burrs is accomplished with simple technical means and reducedwear on tools and without pulses produced by hammering.

The apparatus of the present invention, in which the aforesaid problemis solved, is characterized in that the vibrating movement of thevibration device occurs exclusively in vertical direction, and that aclearance is absent between the contours of the core to be deburred andthe contours of the deburring template, so that the burr is cut off asthe core passes through deburring template.

In accordance with the invention, it has been recognized that anexcessive pulsating or beating of the apparatus can be avoided in thatthe burr is not removed by hammering, but rather is cut off. To thisend, the vibration device is designed in a manner in accordance with theinvention so that the vibrating movement of the vibration device occursexclusively in vertical direction, there being no clearance between thecontours of the core to be deburred and the contours of the deburringtemplate. Accordingly, the edge of the deburring template acts like acutting tool which severs the burr from the core in the course of thevibrating movement.

As regards an accurate adaptation of the vibrating movement to the burrto be cut off respectively, it is of special advantage, when theamplitude of the vibration device is preferably infinitely variable.

As regards an adjustment of the deburring template, it is of furtheradvantage, when the deburring template is adjustable by means of settingscrews in two axial directions. As a result, it will be avoided that notonly the burr, but also the periphery of the core is cut or scraped off.

In a special embodiment, the vibration device comprises a vibrating partwith a magnetic vibrator. Further, a vibrating plate with buffers isprovided, wherein the buffers serve to damp the vibrating movement. Toeffectively prevent the vibrating plate from veering sideways, a leafspring is provided which permits the vibration device or respectivelythe vibrating plate to perform a vibrating movement exclusively invertical direction.

Likewise, it is possible to provide in an advantageous manner severaldeburring templates for simultaneously deburring several cores, whichincreases substantially the throughput in particular in an automaticoperation.

Of special advantage is, in particular under the aspect of an automaticoperation of the apparatus under discussion, when a handling device withelastic grippers is provided, which cooperates with the vibrationdevice. This handling device serves to carry out automatically theoperations from the removal of cores ejected from a core die, via theplacement of the cores into the deburring template, to the furthertransportation of the cores for subsequent handling. The provision ofsuch a handling device permits automatic manipulations, with theelasticity of the grippers preventing damage to the foundry cores or thelike.

In a further advantageous manner, a guide mechanism is provided which isoperative between the handling device and the base carrying thevibration device. This guide mechanism allows to ensure that theworkpiece to be deburred can be placed accurately into the deburringtemplate and be moved out again without damage to the workpiece.Furthermore, the holding of the core in the grippers is made flexible,which again lessens considerably the risk of damaging the workpiece tobe deburred.

Two possibilities exist to configure and further develop the teaching ofthe present invention in an advantageous manner. To this end, referenceis made to the following detailed description of an embodiment of thepresent invention in conjunction with the drawing, in which:

FIG. 1 is a schematic view of an embodiment of an apparatus inaccordance with the invention for deburring foundry cores; and

FIG. 2 shows an apparatus of FIG. 1 rotated by 90° about a verticalaxis.

The apparatus for deburring foundry cores 3 as shown in FIGS. 1 and 2,comprises a handling device 1 with elastic grippers 2 to receive thefoundry cores 3. The foundry cores 3 are automatically removed by meansof the handling device 1 from a core die not shown in the Figures, andbrought over a deburring device comprising a deburring template 4.Arranged on a stationary base 10 is a vibrating part with a magneticvibrator 8, a vibrating plate 5, with buffers 6, and with leaf springs7. The deburring template 4 is also associated to the base 10.

As the core 3 passes through the deburring template 4, the handlingdevice 1 is guided in the stationary part or respectively base 10 suchthat the burr is in a way cut off. A guide mechanism 9 is operativebetween the base 10 and the handling device 1.

Finally, it should be noted that the gist of the present invention,namely deburring by cutting the burr off, is by no means limited to theforegoing embodiment which has been described only by way of example.

That which is claimed is:
 1. An apparatus for removing burrs whichprotrude from the peripheral edge of a workpiece and comprisingatemplate having a rigid internal profile which closely conforms to theentire outline of the peripheral edge of the workpiece, with nosignificant clearance therebetween, means for supporting the workpieceso that the peripheral edge of the workpiece is aligned in apredetermined direction with said internal profile of said template,means for vibrating said template so that the template moves exclusivelyalong said predetermined direction, and means for guiding said workpiecesupporting means for linear movement along said predetermined directionand so that the supported workpiece moves through said internal profileof the template and so that the internal profile acts to sever theprotruding burrs from the peripheral edge of the workpiece.
 2. Theapparatus as defined in claim 1 wherein said means for vibrating saidtemplate includes means for selectively varying the amplitude of thevibrations.
 3. The apparatus as defined in claim 1 further comprising arigid base, and a plate supporting said template, and wherein said meansfor vibrating said template comprises means mounting said plate to saidbase so that said plate can move exclusively in said predetermineddirection with respect to said base, and vibrator means connected tosaid plate.
 4. The apparatus as defined in claim 3 wherein said meansmounting said plate to said base comprises a plurality of leaf springsand a plurality of buffers.
 5. The apparatus as defined in claim 3wherein said guiding means includes cooperating male and female membersmounted to respective ones of said workpiece supporting means and saidbase.
 6. The apparatus as defined in claim 1 wherein said workpiecesupporting means includes elastic grippers for engaging said workpiece.7. A method for deburring a workpiece such as a molded foundry corecomprising the steps ofproviding a workpiece having burrs which protrudefrom the peripheral edge thereof, providing a template having a fixedinternal profile which closely conforms to the entire outline of saidperipheral edge of the workpiece, with no significant clearancetherebetween, supporting the workpiece and the template so that theperipheral edge of the workpiece is aligned in a predetermined directionwith said internal profile of said template, vibrating said template sothat the template moves exclusively along said predetermined direction,and guiding said workpiece supporting means for linear movement alongsaid predetermined direction and so that the supported workpiece movesthrough said internal profile of the vibrating template and the internalprofile acts to sever the protruding burrs from the peripheral edge ofthe workpiece.